Dry shaver with two cutting units



April 29, 1969 w c ET AL SHAVER WITH TWO CUTTING UNITS DRY Sheet Filed May 2, 1967 lnvenzon; WW mM s April 29, 1969 R w ET AL 3,440,724

DRY SHAVER WITH TWO CUTTING UNITS Filed May 2, 1967 Sheet 2 of 2 lnyentor IN. Q

United States Patent US. Cl. 3034.1 7 Claims ABSTRACT OF THE DISCLOSURE An electrically powered dry shaver comprising a housing for a motor having an oscillatable output member which is permanently connected with the movable part of a first hair cutting or shaving unit whose stationary part is constituted by a comb foil. The shaver further includes a second hair cutting or trimming unit having a stationary cutting member and an oscillatable or reciprocable cutting member which is normally disengaged from the output member. A coupling which can be operated by hand includes a coupling element which can establish a driving connection between the output member and the cutting member at the users will. When the trimming unit is not in use, the coupling element is disengaged from the output member and also from the cutting member.

Background of the invention The present invention relates to dry shavers in general, and more particularly to improvements in electrically powered dry shavers of the type comprising a customary shaving unit composed of a comb foil and an oscillatory cutter and a trimming unit which can be used to sever hairs of sideburns, mustaches or other relatively long hirsute growths. As a rule, the trimming unit comprises a fixed comb-like cutting member which is secured to the head of the housing adjacent to the foil and a reciprocable comb-like cutting member which can be driven in automatic response to starting of the motor or at the users will. The trimming unit should not interfere with operation of the shaving unit, or vice versa. When the two units are operated simultaneously, the energy requirements of the motor increase or the trimming unit uses up energy at the expense of the shaving unit, depending on the size of the motor.

Power-operated dry shavers wherein the trimming unit can be operated independently of or together with the shaving unit normally comprise a coupling which is operative only when the trimming unit is to be put to use. Presently known couplings for such trimming units are not entirely satisfactory, either because they comprise an excessive number of parts, because they are too expensive, because their moving parts contribute excessively to the total mass of moving parts when the trimming unit it in use, or because they occupy too much room which is at a premium in a dry shaver. For example, it was already proposed to use a trimming unit which is pivotable into and from the housing and wherein the driving connection between the motor and the trimming unit is established in automatic response to movement of the trimming unit to exposed or operative position. In such dry shavers, the housing must be large enough to accommodate the trimming unit. The hinges and other parts which are necessary to permit and control pivotal movements of the trimming unit involve additional manufacturing and installation costs. The chamber which accommodates the trimming unit in retracted position is likely to accumulate particles of hair and/or other foreign matter which must be removed at frequent intervals. The construction of couplings which become operative in re- 3,440,724 Patented Apr. 29, 1969 spouse to bodily displacement of the trimming unit with reference to the housing is complicated and such couplings are prone to malfunction.

In accordance with another prior proposal, the coupling for the trimming unit comprises a coupling element which is mounted on and shares movements of the output member. Such solution is not satisfactory because the wear on the coupling is very high, because it is often difficult to establish without undue delay or effort a driving connection between the output member and the movable cutting member of the trimming unit, and also be cause the coupling element oscillates, reciprocates or spins with the output member and thus contributes its mass to the mass of moving parts even when the trimming unit is not in use.

Accordingly, it is an important object of our invention to provide a dry shaver of the type wherein a shaving unit can be used together with or'independently of the trimming unit and to provide such dry shaver with a novel and improved coupling for the movable cutting member of the trimming unit.

Another object of the invention is to provide a dry sha'ver of the just outlined character wherein the trimming unit need not be bodily displaced with reference to the housing in order to establish a driving connection between its movable member and the prime mover.

A further object of the invention is to provide a dry shaver wherein the mass of moving parts is relatively small when the shaving unit is used alone and wherein such mass is increased negligibly when the operator decides to use the trimming unit.

An additional object of the instant invention is to provide a novel coupling element for use in a coupling of the above outlined character.

A concomitant object of the invention is to provide a coupling wherein the parts are subjected to little wear, wherein the movable parts automatically return to a predetermined position when the trimming unit is not in use, and which is constructed and assembled in such a way that it allows for ready detachment or attachment of the prime mover and/ or trimming units.

Summary of the invention Our invention is embodied in a power-operated dry shaver which comprises a customary housing, a prime mover which is constituted by a small electric motor installed in the interior of the housing and including a movable output member, a first hair cutting or shaving unit having a first cutting part in the form of a comb foil mounted on the housing and a second cutting part movable relative to the internal surface of the foil and operatively connected with the output member, a second hair cutting or trimming unit having a comb-like cutter carried by the housing and a cutting member movable relative to the cutter, and novel coupling means including a coupling element movable between a first position of full disengagement from the output member and cutting member and a second position in which it transmits motion from the output member to the cutting member to operate the second cutting unit.

The coupling means preferably further comprises an actuating element which is reciprocable with reference to the housing and is pivotably connected with the coupling element. The latter comprises a slotted annulus which can establish a driving connection between a male portion of the output member and a female portion of the cutting member when the coupling element is moved to second position. The arrangement is preferably such that an internal surface of a first part of the annulus then engages the male portion while an external surface of a second part of the annulus engages with the female portion.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved dry shaver itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of a specific embodiment with reference to the accompanying drawing.

Brief description of the drawing FIG. 1 is a side elevational view of a dry shaver which embodies one form of the present invention, portions of the housing and of the foil being broken away;

FIG. 2 is an enlarged fragmentary sectional view as seen in the direction of arrows from the line 2-2 of FIG. 1;

FIG. 3 is an enlarged view of a first detail of the struc ture shown in FIG. 1; and

FIG. 4 is an enlarged view of a second detail of the structure shown in FIG. 1.

Description of the preferred embodiments Referring first to FIGS. 1 and 2, there is shown a power-driven dry shaver which comprises a customary housing 1 accommodating a mounting plate 2 for a prime mover in the form of an electric motor. This prime mover comprises a U-shaped stator 3 serving as a means for imparting oscillatory movements to an output member or armature 7 which is rockable about the axis of a pivot pin 6 carried by the mounting plate 2. The stator 3 comprises two windings 4, 5.

The dry shaver further comprises a first hair cutting or shaving unit A and a second hair cutting or trimming unit B. The unit A includes a fixed cutting part here shown as a conventional comb foil and a movable cutting part 9 which is operatively connected with the output member to be reciprocated during oscillation of the member 7. The upper end portion 8 of the output member 7 constitutes an arm which is permanently connected with the movable cutting part 9. The manner in which the parts 9, 10 of the cutting unit A cooperate to sever whiskers which penetrate through the apertures of the part 10 is well known from the art of dry shavers. The fixed part 10 is attached to a frame 11 which constitutes the upper portion or head of the housing 1. This frame 11 also carries the stationary cutter 12 of the second hair cutting unit B, the latter serving to trim longer hairs, for example, the sideburns or the mustache. The cutter 12 resembles a comb and cooperates with a movable comblike cutting member 13 in a manner known from the art of conventional hair clippers.

Our present invention resides in the provision of a novel coupling, best shown in FIGS. 2 to 4, which enables the operator to start or terminate reciprocatory or oscillatory movements of the movable cutting member 13 in the second hair cutting unit B by establishing or terminating a driving connection between the arm 8 of the output member 7 and the cutting member 13. The arm 8 is provided with a male portion 14 which resembles a post or stud and extends into a forked female portion 15 which is rigid or integral with the cutting member 13 of the unit B) with such clearance that the male portion 14 can share oscillatory movements of the output member 7 without causing any movements of the cutting member 13. The male portion 14 is parallel with the pivot pin 6 on the mounting plate 2. The prongs 15a, 15b of the forked female portion 15 are best shown in FIG. 4. When the user wishes to remove whiskers from his face, the second cutting unit B is preferably idle so that the output member 7 merely reciprocates the cutting part 9 which cooperates with the foil 10 to sever the whiskers along the internal surface of the foil.

The aforementioned coupling further comprises a slidelike actuating element 16 which is accommodated in the housing 1 and has an outwardly extending guide pin 18 passing through an elongated guide slot 17 of the housing 1. The pin 18 carries a knob 19 which is outwardly adjacent to the housing 1 and may be manipulated by hand to shift the actuating element 16 in and counter to the direction indicated by arrow 33 (FIG. 4). The upper part of the actuating element 16 (as viewed in FIG. 1, 2 or 3) is provided with a groove or recess 20 for a substantially T-shaped coupling element 21 which can establish a driving connection between the male portion 14 of the output member 7 and the female portion 15 of the cutting member 13. The coupling element 21 is rockable on a pivot pin 22 of the actuating element 16 and is biased by a torsion spring 23 which tends to maintain it in a neutral or median position intermediate two end positions. The pivot pin 22 is parallel to the pivot pin 6. The spring 23 is coiled around a stud 24 on the actuating element 16 and its terminals 23a, 23b bear against two bent-over projections 21a, 21b of the coupling element 21. The latter further comprises two projections 32a, 32b which respectively engage with the terminals 23a, 23b opposite the projections 21a, 21b. The projections 21a, 21b and 32a, 32b are best shown in FIG. 3.

The upper portion 21c of the coupling element 21 is rigid or integral with a two-part slotted annulus 25 which serves as a means for establishing a motion transmitting connection between the male portion 14 and female portion 15 when the actuating element 16 causes the coupling element 21 to move from a lower or first position to an upper or second position. The first part of the annulus 25 comprises two upwardly diverging wings 26, 27 which can engage the male portion 14 when the coupling element 21 is moved to second position whereby the male portion 14 causes the annulus 25 and coupling element 21 toshare oscillatory movements of the output member 7. The coupling element 21 then rocks back and forth about the pivot pin 22 and its projections 32a, 32b and 21a, 21b act upon the terminals 23a, 23b of the torsion spring 23. At the same time, a slotted boss-like or cylinder-like second part 5 of the annulus 25 enters the clearance between the prongs 15a, 15b of the female portion 15 on the one hand and the free end of the male portion 14 on the other hand so that the cutting member 13 will be reciprocated by the oscillatory movements of the output member 7. The slot 25a of the annulus 25 is just wide enough to accommodate the male portion 14, and the diameter of the boss-like part 25' is identical with or approximates the width of the gap between the prongs 15a, 15b. It can be said that, when the coupling element 21 is moved to its second or upper position, an internal surface of the annulus 25 (on the wings 26, 27) engages wtih the male portion 14 and an external surface of the annulus (on the part 25') engages with the female portion 15.

The strokes of the actuating element 16 are preferably short, i.e., the annulus 25 can be held at a level immediately below the male portion 14 when the coupling element 21 is moved to the first or lower position. In the second or upper position of the coupling element 21, the space between the wings 26, 27 is in registry with the space between the prongs 15a, 15!), as seen in the axial direction of the male portion 14. At the same time, the pivot pin 22 is preferably coaxial with the pivot pin 6. This eliminates uncontrolled movements of the coupling element 21 with reference to the output member 7 when the male portion 14 transmits oscillatory movements to the female portion 15 and cutting member 13.

In the second or raised position of the coupling element 21 (shown in FIG. 4 by broken lines), the wings 26, 27 abut against the prongs 15a, 15b of the female portion 15 and guide the annulus 25 while the latter shares movements of the output member 7 and transmits such movements to the cutting member 13.

The coupling of our invention is further provided with a detent means which can yieldably locate the coupling element 21 in one or both positions with reference to the male and female portions 14, 15. In the illustrated embodiment, the detent means comprises a first detent member 1a provided on the housing directly below the actuating element 1 6 and having two vertically spaced throat portions or constrictions 28, 29 each of which can accommodate the tips' of two resilient blade-like detent members 30, 31 provided on the actuating element 16. When the tips of thejd'tent members 30, 31 extend into the lower throat portion 29, the coupling element 21 is yieldably held in the lower end position in which the hair cutting unit B is idle. If the user wishes to utilize the unit B, he or she must overcome the bias of the detent member 30, 31 by exerting against the knob 19 an upwardly directed force in order to move the tips of detent members 30, 31 into'the upper throat portion 28.

An important advantage of the improved dry shaver is that the second cuttin'g'ilnit B can be started 'or inactivated whenever the user sojdesires, with a minimal elfort, and with little loss in time. The knob 19 is preferably positioned in such a way that one hand suflices to hold the housing 1 and to effect movement of the coupling element 21 to upper or lower position.

Another important advantage of our dry shaver is that the coupling element 21 shares movements of the output member 7 only at such times when the second cutting unit B is in actual use. This reduces the wear on the coupling element and the combined mass of oscillating parts when the operator does not wish to use the unit B. Moreover, and when the coupling element 21 is not in engagement with the output member 7 and cutting member 13, the entire cutting unit B and the foil 10 of the cutting unit A can be removed withthe frame 11 to permit inspection and/or cleaning of the shaver parts. The entire prime mover inclusive of its mounting plate 2 can be installed or removed independently of the coupling and frame 11.

The material of the coupling element 21 can be selected at will, i.e., this element need not consist of the same high-quality material as the cutting member 13 and/or the output member 7. For example, the coupling element 21 may consist of tough, lightweight, wear-resistant synthetic plastic material so that its mass contributes only insignificantly to the overall mass of moving parts when the prime mover drives the cutting member of the unit B.

Since the spring 23 invariably tends to maintain the coupling element 21 in a median or neutral angular position, and since the boss-like part 25' of the annulus 25 on the coupling element 21 then registers with the space between the prongs 15a, 15b of the female portion 15, the part 25 invariably-finds its way into such' space when the operator decides to push the knob l9 upwardly to start the cutting unit B.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of our contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

We claim:

1. A dry shaver comprising a housing; a prime mover installed in said housing and including a movable output member; a first hair cutting unit having a first cutting part carried by said housing and a second cutting part movable relative to said first part and arranged to receive motion from said output member; a second hair cutting unit including a stationary cutter firmly mounted in fixed position to said housing and a movable cutting member mounted for oscillatory movement relative to said cutter member adjacent thereto; and independent coupling means including a coupling element movable between an uncoupling position disengaged from both said members and a coupling position in engagement with both said members in which latter position it transmits motion from said output member to said movable cutting member mounted for oscillating movement permanently adjacent to said stationary cutter.

2. A dry shaver as defined in claim 1, wherein said coupling element is mounted oscillatably so as to be adapted to be oscillated by said output member and to transmit its oscillating movement to said movable cutting member.

3. A dry shaver as defined in claim 1, wherein said coupling means further comprises pivot means rockably connecting said coupling element to said actuating element, said coupling element being rockable on said pivot means between two end positions and through an intermediate positionv and said coupling means further comprising biasing means for urging said coupling element to neutral position.

4. A dry shaver as defined in claim 1, wherein said prime mover further includes pivot means for said output member and said coupling means further comprises and actuating element operative to move the coupling element between said first and second positions and second pivot means connecting said elements, said second pivot means being coaxial with said first mentioned pivot means in the second position of said coupling element.

5. A dry shaver as defined in claim 1, wherein said coupling means further comprises actuating means operative to move the coupling element between said first and second positions and detent means cooperating with one of said elements for yieldably locating said coupling element in at least one of said positions.

6. A dry shaver as defined in claim 1, wherein said prime mover further comprises means for oscillating said'output member, one of said members comprising a female portion and the other member comprising a male portion extending into said female portion with sufiicient clearance to permit oscillatory movements of said output member while said cutting member remains at rest, said coupling element comprising a first part which engages with said male member and a second part which fills said clearance in the second position of said coupling element whereby the first and second parts of said coupling element transmit motion between said male and female portions.

7. A dry shaver as defined in claim 6, wherein said female portion is constituted by a fork rigid with said cutting member, said fork having two prongs receiving the male portion with said clearance therebetween, said first part of the coupling element comprising a pair of divergent wings which abut against said prongs in the second position of said coupling element.

References Cited UNITED STATES PATENTS 2,574,317 11/1951 Berg 30-34.1 2,873,520 2/1959 Schnapp et al 30-341 2,917,824 12/1959 Brauss 3034.1

FOREIGN PATENTS 1,262,046 4/1961 France. 1,004,520 3/ 1957 Germany. 1,051,161 2/1959 Germany.

827,768 6/1958 Great Britain.

353,652 5/ 1961 Switzerland.

MYRON C. KRUSE, Primary Examiner. 

